Japanese Industrial Standards (JIS) X 0510:2004 “Two dimensional symbol—QR code—” describes a technique of a two-dimensional (2D) barcode, by which a graphic code is read and information contained in the code is retrieved. There is also a technique for concealing hidden-object information (representing information not to be displayed) in such a 2D barcode. Concealing hidden-object information in a 2D barcode otherwise having a standard appearance can support applications in industries that handle cryptographic key information or personal information.
Patent Literature 1 discloses transmitting information using a 2D barcode. Patent Literature 2 discloses a delivery management system which can protect the personal information of a sender or a receiver.